Quercetin

Among the polyphenol phytochemicals found in blueberries, broccoli, onions, and green tea is the flavonoid quercetin (Li et al., 2021).  Quercetin is also found in apples and grapes (Gugliandolo et al., 2020).  Sanver et al. describe the structure of quercetin in a peer-reviewed primary article; they found that the different structures of different types of flavonoids influenced their behavior when they came into contact with a phospholipid membrane.  They characterized quercetin as being more planar than some of the other flavonoids, and propose that this structural characteristic is instrumental to a stabilization of the membrane, building on studies they reference regarding mast cells (Sanver et al., 2016).

 

Primary peer-reviewed research by Gugliandolo et al. studied the ingestion of mycotoxins by mice, and found an association of quercetin (30 mg/kg) with reduced neurological impairment.  They were able to measure statistically significant (p-values less than 0.05) effects of quercetin in preventing both the oxidative stress and the increase of cytokines that they had seen after exposure to the mycotoxins.  Quercetin fully ameliorated the effects of the mycotoxins in the area of anxiety, and partially in the area of memory (Gugliandolo et al., 2020).

 

Li et al., also in primary peer-reviewed research, investigated quercetin (20 and 50 mg/kg) as a possibility to prevent a common scenario where new bone cells begin to grow in the wrong place following an injury.  They found a statistically significant (P<0.05) success rate in the mouse model.  They suggest that the mechanism here has to do with quercetin’s ability to damp down the cytokine response to trauma that comes from mast cells (Li et al., 2021).

 

Mast cells are involved in many health conditions, including allergies.  Might quercetin be able to modulate patient outcomes for all of these, representing one facet of the countless benefits of a diet rich in fruits and vegetables?

 

Ramps (wild leeks) are a traditional spring tonic where I live in the Appalachian mountains.  Peer-reviewed primary research by Dabeek et al. concluded that there is 50 mg of quercetin in a serving of ramp leaves (100g), while describing several forms of quercetin that may be more or less likely to be metabolized (Dabeek et al., 2019).  This makes it seem unlikely to obtain 1-3 grams of quercetin from food sources, in order to approximate the /kg equivalent dose used in the rodent research.  Kaempferol was the other flavonoid found in ramps by Dabeek et al.,(Dabeek et al., 2019), and kaempferol was also the other flavonoid characterized by Sanver et al. as planar (Sanver et al., 2016).

 

The higher doses used in the studies suggest using supplements as a way to achieve a therapeutic dose.  Caution is warranted however.  It would be wise to research the effects on humans rather than relying on data from rodent trials, and since quercetin affects the cell membrane in such a dramatic way it would be wise to monitor the patient for any new symptoms that might arise, and evaluate the possibility that they could be related to the quercetin supplementation. 

 

 

 

References

Dabeek, W. M., Kovinich, N., Walsh, C., & Ventura Marra, M. (2019). Characterization and Quantification of Major Flavonol Glycosides in Ramps (Allium tricoccum). 

 

Gugliandolo, E., Peritore, A. F., D’Amico, R., Licata, P., & Crupi, R. (2020). Evaluation of Neuroprotective Effects of Quercetin against Aflatoxin B1-Intoxicated Mice. Animals : an open access journal from MDPI, 10(5), 898.  

 

 Li, J., Sun, Z., Luo, G., Wang, S., Cui, H., Yao, Z., Xiong, H., He, Y., Qian, Y., & Fan, C. (2021). Quercetin Attenuates Trauma-Induced Heterotopic Ossification by Tuning Immune Cell Infiltration and Related Inflammatory Insult. Frontiers in immunology, 12, 649285.  

 

Sanver, D., Murray, B. S., Sadeghpour, A., Rappolt, M., & Nelson, A. L. (2016). Experimental Modeling of Flavonoid-Biomembrane Interactions. Langmuir : the ACS journal of surfaces and colloids, 32(49), 13234–13243.